package com.jk.util;

import org.apache.commons.lang3.StringUtils;

import javax.servlet.http.HttpServletRequest;

/**
 * Created by yanghuan on 2015/7/20.
 */
public class IpUtil {

    //将127.0.0.1形式的IP地址转换成十进制整数，这里没有进行任何错误处理
    public static long ipToLong(String strIp) {
        long[] ip = new long[4];
        //先找到IP地址字符串中.的位置
        int position1 = strIp.indexOf(".");
        int position2 = strIp.indexOf(".", position1 + 1);
        int position3 = strIp.indexOf(".", position2 + 1);
        //将每个.之间的字符串转换成整型
        ip[0] = Long.parseLong(strIp.substring(0, position1));
        ip[1] = Long.parseLong(strIp.substring(position1 + 1, position2));
        ip[2] = Long.parseLong(strIp.substring(position2 + 1, position3));
        ip[3] = Long.parseLong(strIp.substring(position3 + 1));
        return (ip[0] << 24) + (ip[1] << 16) + (ip[2] << 8) + ip[3];
    }

    //将十进制整数形式转换成127.0.0.1形式的ip地址
    public static String longToIP(long longIp) {
        StringBuffer sb = new StringBuffer("");
        //直接右移24位
        sb.append(String.valueOf((longIp >>> 24)));
        sb.append(".");
        //将高8位置0，然后右移16位
        sb.append(String.valueOf((longIp & 0x00FFFFFF) >>> 16));
        sb.append(".");
        //将高16位置0，然后右移8位
        sb.append(String.valueOf((longIp & 0x0000FFFF) >>> 8));
        sb.append(".");
        //将高24位置0
        sb.append(String.valueOf((longIp & 0x000000FF)));
        return sb.toString();
    }

    //获取用户真实ip
    public static String getUserIp(HttpServletRequest request) {
        String ip = request.getHeader("X-Forwarded-For");
        if (StringUtils.isNotBlank(ip) && !"unknown".equalsIgnoreCase(ip)) {
            // 多次反向代理后会有多个IP值，第一个不为 unknow 的才为真实IP
            String[] ips = StringUtils.split(ip, ",");
            for (String i : ips) {
                i = StringUtils.trim(i);
                if (StringUtils.isNotBlank(i) && !"unknown".equalsIgnoreCase(i)) {
                    ip = i;
                    break;
                }
            }
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("WL-Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_CLIENT_IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_X_FORWARDED_FOR");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getRemoteAddr();
        }
        return ip;
    }
}
